Currently, a dry separation process of overspray is used in the paint workshops of major vehicle manufacturers for handling paint overspray, and such process enables the coating production to get closer to the goal of “green” since it not only reduces energy consumption by 60% and fresh water consumption by 44% but also reduces the carbon dioxide emission by about 33% as compared to the traditional painting workshops. Said technology utilizes a dry purification device to handle the paint mist, and one of the main features of this new technology is to use limestone powder as binding agents. Using limestone powder as a binding agent and the dry particles of overspray are taken away via the air circulation. Said dry separation treatment process of overspray uses tap water and water treatment chemicals no longer, and thus no wastewater is discharged. The limestone powder containing paint slag is the major waste from this process.
Currently, the saturated waste limestone powder after the usage is disposed by way of incineration. And this not only costs high disposal expenses annually but also brings about certain of environmental protection burden, and the incineration disposal process inevitably consumes a lot of energy and tends to cause a second pollution. If the waste limestone powder could be utilized as a feedstock or even be re-used in the automobile manufacturing, then the waste generated during the manufacturing process would be consumed in the automobile manufacturing links, and the environmental burden caused to the society is zero, which saves a lot of human and material resources.
An asphalt damping sheet is a damping sheet using asphalt and non-metallic minerals as raw materials. An asphalt damping sheet as a viscous-elastic material can be attached to the inner surface of vehicle body and can be glued tightly to the steel wall of the vehicle body mainly for reducing noise, reducing vibration and isolating the vibration transmission pathway, i.e. acts as a damper. At the present time, almost all domestic passenger cars are equipped with asphalt damping sheets.